Alabama Blue Star Quartz
How the hunt began
I have hunted gemstones all over the world, so when I heard that the state gemstone of Alabama was the blue star quartz, naturally my interest was piqued. I have seen star rose quartz, star girasol, star smokey quartz, and even a star oro verde quartz, but I had never seen a cut example of a star blue quartz. Even though asterism is common in microscopic samples of blue quartz, there are few examples the size of cut gems. One of the problems with blue quartz itself is the color. There are several reasons quartz can be blue, a couple of which are the distribution of dumortierite in the stone and Rayleigh scattering. I went online and found several sources which advertised blue quartz. When ordered, what arrived was usually dumortierite quartz. Other “blue quartz” turned out to be blue chalcedony. In one instance, blue star quartz was advertised, and what arrived was indeed quartz with blue star shaped inclusions of dumortierite (afghanistani material), but it was not the asterism that I desired. There was a single picture of a star “blue” quartz on the net and I decided that I had to have an example of this material.
Bad information:the first obstacle
My son and I have made it a mission to locate a good source for the gemstone for the state of Alabama. This has proven to be a difficult task. Between misinformation, disbelief of rockhounds, the unique geology of Alabama and the undependable manifestation of the phenomenon itself, it has been an uphill battle.
One of the biggest setbacks was the misinformation that Blue star quartz can be found along the Flint river in Madison county. Nothing could be further from the truth! There is an abundance of blue flint, which may be attractive if cut en cabochon, but it lacks the crystal structure to support asterism. In fact, it is impossible for the gem to form in that area. So, after exploring the entire Flint river, I decided to investigate the claims of the “flint river star quartz”. Essentially, all accounts lead back to a single article from an old rockhounding magazine, with no real first hand accounts of discovery.
Chasing a myth?
Perhaps this misinformation is what led to the second obstacle: disbelief of rock hounds. Having followed the rumor of the Flint river, any gem hunter would naturally doubt the existence of such a beast. The State museum did have a cut example of the stone, albeit small; so there are one of two things that could have happened. Either the stone is found elsewhere in the state, or someone convinced the curators that a stone from some other locality was found and cut within the state.
Clues from geology lead to success
My son and I turned our attention to the third obstacle: the unique geology of Alabama. We focused on the Piedmont formation which runs along the Central, Eastern part of Alabama. Blue quartz, commonly asteriated or chatoyant can be found throughout the Piedmont formation in Georgia, the Carolinas and Virginia. As a boy, long before I became a gem junkie, I had remembered seeing sky blue quartz in Virginia. So, the likely place to find blue quartz in Alabama was obviously the Piedmont formation, meaning that any stones found were probably a billion years old! It was here that we had modest success. Because Alabama rests on the end of the Piedmont formation, there is heavy sedimentation above it, unlike other parts of the formation where deep rock in place formations are exposed.
We were able to locate a few pounds of the material and take it back to Florida for examination. Upon cutting and sampling cores from the rocks, most had no light phenomenon at all. The ones that did only showed spotty chatoyance under a high magnification. This is because the rocks were made up of very small quartz crystals that were oriented in various directions and had grown into one another, yet no crystal large enough to yield a decent sized cut stone with the phenomenon. This was not a setback, however, it is actually a step toward our goal of finding a viable source for decent sized gems within the state. Any larger stones would likely be recovered from either a deeper layer of the formation or have been washed into the area from the multiple glacial melts that flooded the area over the last billion years. Vindication of this idea came from a single river tumbled stone found under a bridge crossing in the area. While it was made up of a series of crystals slightly larger than a pencil in diameter, it was possible to cut a small cab with a star. The down side of this though, is that there is so much iron diffused in the stone that the blue is not as deep as anticipated when cut.
Is it really blue?
Another observation is that the Alabama blue quartz is more of a steel blue grey than a true blue. The only photograph of a blue star quartz that I could find on the internet is this deep grey color with a 4 ray star and it in itself is a tiny stone (see above). The stone that I was able to cut from a fairly blue piece of rough appeared, for the most part, clear with a slight yellowish haze (due to iron oxide). The star was poor, and faint while the blue color was more visible on the axis with the asterism.
No transmission star
Due to the included nature of the stone, it was not possible to display the star via the transmission mode i.e. shining the light through the stone or mirroring the back of the stone. This may not be true for all examples found in the state, but it sure applies to this sample!
Humble but happy
Albeit a humble example, this is evidence that star blue quartz does indeed exist in Alabama. Further excursions into the area are bound to yield better examples than I have been able to acquire. It is worth noting that while my material seemed sufficiently dark, the cut version pictured at the beginning of this article must have seemed almost black prior to cutting and had an incredible amount of “silk”.
A Texas source?
On an interesting side note, my son and I went to West Texas searching for blue topaz in the Llano uplift. While we had “no joy” on the topaz, we found a considerable amount of blue quartz. It differs a little from the Alabama material, yet it may hold some promise of producing blue star gems, but that is another article!